Controlling spatially restricted intracellular protein-activity during embryonic neuronal development using biomagnetic nanotechnologies During mammalian embryonic development, neuronal cells polarize to create distinct cellular compartments of the axon and dendrite that inherently differ in the molecular composition of their cytoplasm, cytoskeleton, and plasma membrane. These differences underlie the unique morphology and function of these compartments and are responsible for directed information flow in the brain. Whereas axons transmit the chemical and electrical neuronal signals, the dendrites receive and integrate them. This polarized architecture arises from precisely regulated spatial segregation of specific intracellular proteins? activities to discrete subcellular regions of a single neuronal cell that respectively dictate the axonal vs. dendritic fate. Aberrations in the localization of these proteins? activity lead to defective neuron polarization and underlie severe human neurodevelopmental pathologies including intellectual and motor disabilities, epilepsy, and autism spectrum disorders. The ability to exert precise spatio-temporal control on intracellular protein-activity would permit directed regulation of neuronal polarization and may provide new approaches for the repair of the underlying neurodevelopmental pathologies. To date, no existing technologies, including leading molecular-genetics, light-controlled protein activation, or their combination using optogenetics, can allow sustained spatial restriction of intracellular protein-activity in the developing neuron. The main objective of this study is to address this fundamental challenge in neurobiology by developing biomagnetic-based nanotechnologies that will enable the spatial and temporal control of intracellular protein function in developing embryonic neurons. Specifically, we will develop biomagnetic-nanotechnologies to deliver and retain localized activity of the kinase LKB1, to dictate the process of axon formation in embryonic neurons in culture. Such a proposal demands a multi-disciplinary approach that integrates neurobiology, material engineering, and bioelectronics, for the development of protein based neuro-therapeutics. Many cellular events that dictate cell morphogenesis, metabolic state, or its unique physiological functions, in all cell types across evolutionarily distant species, are determined by highly localized and timed activity of specific intracellular proteins. The causative role of a critical intracellular protein in a particular cellular event or the ability to control that event can only be achieved by directed subcellular localization and retention of the protein or its activity. As current methodologies for spatio-temporal manipulation of protein function are inherently incapable of allowing the long-term spatial confinement of protein function, our studies will be applicable to many fundamental cellular events, as polarization and migration, and to the many intracellular proteins that control these cellular processes.
Significance of the proposed research The fundamental event of axon formation during embryonic neuronal development is regulated by intracellular protein activity in a highly spatio-temporal manner. We will develop biomagnetic-based nanotechnologies for directed subcellular delivery and retention of a critical intracellular protein to control the complex and long-term developmental process of axon formation in the developing embryonic neuron, to gain fundamental insight into mechanisms that regulate this developmental process and repair of underlying neurodevelopmental pathologies, including mental and motor disabilities, epilepsy, and autism spectrum disorders.
